Height adjusting mechanism and stool for dental practitioner

ABSTRACT

A height adjusting mechanism for a dentistry stool comprises a support member, a movable height adjusting assembly and a pushbutton actuator. The support member is coupleable to the stool adjacent a seat of the stool. The movable height adjusting assembly is selectively movable up and down relative to the support member. The pushbutton actuator is positionable on a side of the movable height adjusting assembly adjacent a seated user, and is manually actuatable by the seated user to release the movable height adjusting assembly from a locked position at a current height to allow the movable height adjusting assembly to be moved to a new height. The height adjusting mechanism can be implemented to provide a height-adjustable seat back and/or a height-adjustable torso bar.

BACKGROUND

Dental practitioners typically practice from a seated position in whichthey lean forwardly to access the patient, and in particular, thepatient's oral cavity. In addition to providing adequate support, dentaloperatories and other dental work spaces are often confined, so seatingfor practitioners needs to have a small form factor and be highlymobile. Moreover, stools or other seating for practitioners needs toallow easy ingress and egress, particularly because a practitionerattending to multiple patients in several different operatoriesconcurrently throughout an entire day may enter and exit a seatedposition 100 times or more. Further, practitioners range in sizes,practice styles and preferences, so any seating solution useful to apractice with multiple practitioners needs to allow for a range ofadjustment that can be performed simply and quickly.

SUMMARY

Described below are embodiments of a height adjusting mechanism and anassociated practitioner's stool that address some of the drawbacks ofconventional seating for practitioners.

According to a first implementation, a height adjusting mechanism for adentistry stool comprises a support member, a movable height adjustingassembly and a pushbutton actuator. The height adjusting mechanism canbe implemented to provide a height-adjustable seat back and/or aheight-adjustable torso bar. The movable height adjusting assembly isselectively movable up and down relative to the support member. Thepushbutton actuator is positionable on a side of the movable heightadjusting assembly adjacent a seated user, and is manually actuatable bythe seated user to release the movable height adjusting assembly from alocked position at a current height to allow the movable heightadjusting assembly to be moved to a new height.

In some implementations, the height adjusting mechanism includes a seatback coupled to a distal end of the movable height adjusting assembly.In some implementations, the support member includes at least one guidegroove and the movable height adjusting assembly includes at least oneguide member configured to fit within the at least one guide groove.

In some implementations, the movable height adjusting assembly comprisesa rear cover and a front cover, and the front and rear coverssubstantially enclose an engaged portion of the support member. The rearcover can have a U-shaped cross section, and the front cover can beconfigured to fit within and complete the U-shaped cross section. Therear cover can have an inner surface with protruding guide membersconfigured to engage corresponding guide grooves in the support member.The assembly can include a lower cover with an opening shaped to receivethe support member, the lower cover being configured for positioning ata junction of the rear cover and the front cover adjacent their proximalends.

In some implementations, the front cover and the rear cover fit togetherto surround the support member, and the front cover and the rear coverhaving smooth outer surfaces to enhance the aesthetic appearance and tofacilitate cleaning.

In some implementations, the front cover includes a cutout shaped toreceive the pushbutton actuator, and the assembly includes a biasedengagement member coupled to its inner surface. The pushbutton actuatorcan be depressible to contact the engagement member and urge it out ofengagement with the support member to permit the movable heightadjusting assembly to be moved relative to the support member. In someimplementations, the biased engagement member is coupled to the rearcover. The support member can have a series of spaced recesses, and theengagement member can be biased to contact one of the recesses. In someimplementations, there is a plate configured to be coupled to the rearcover with the support member positioned between the plate and the rearcover.

In some implementations, the support member has an angled proximal endwith apertures, and the angled proximal end is configured for couplingthe support member rearward of a seat of the stool.

In some implementations, the pushbutton actuator is positionable withinarm's reach of the seated user and is actuatable using a single hand.

According to another implementation, a stool for dentistry comprises aleg assembly with multiple feet, a seat assembly supported by the legassembly and having a seat, a height adjusting mechanism having asupport member coupleable to the stool adjacent the seat, a movableheight adjusting assembly that is selectively movable up and downrelative to the support member and an actuator positionable on a side ofthe movable height adjusting assembly adjacent a seated user. Theactuator can be manually actuatable by the seated user to release themovable height adjusting assembly from a locked position at a currentheight to move the movable height adjusting assembly to a new height,e.g., to change a height of a seat back (and/or a torso bar) positionedat a distal end of the height adjusting mechanism.

The stool can include an optional tilt mechanism configured to permitthe support member to selectively tilt relative to the seat assembly inresponse to force from a seated user. The stool can include optional armrests that are height adjustable and pivotable.

The foregoing and other features and advantages of the disclosedembodiments will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B are perspective views of a practitioner's stoolaccording to a first implementation.

FIG. 2A is an exploded perspective view of an adjustment assembly forchanging a height of a seat back on the stool of FIG. 1.

FIG. 2B is an enlarged perspective view showing part of the stool ofFIG. 1 with portions of the adjustment assembly cutaway to show itsinternal components.

FIGS. 3A-3C are front elevation views of a stool similar to the stool ofFIG. 1, but having adjustable armrest assemblies and armrests.

FIG. 4 is an exploded perspective view of a portion of the adjustablearmrest assemblies.

FIG. 5 is an enlarged section view in elevation of a portion of oneadjustable armrest assembly of FIG. 4.

FIGS. 6A-6D are schematic plan views of a stool having two adjustablearmrest assemblies and showing various positions in which the armrestscan be positioned relative to each other and the rest of the stool.

FIG. 7 is a perspective view of a stool according to anotherimplementation.

DETAILED DESCRIPTION

FIGS. 1A and 1B are perspective views from different sides of anembodiment of a practitioner stool 100. The stool 100 has a seat backassembly 102, which extends from a seat assembly 104. The seat backassembly 102 and the seat assembly 104 are supported by the leg assembly106. As shown, the leg assembly 106 has a center support from whichmultiple legs with casters extend.

The seat assembly 104 includes a seat 108 shaped to support apractitioner in a seated position. The seat back assembly 102 isadjustable to change a height of a seat back 110 coupled to its upperend. At a lower end, the seat back assembly 102 has a support 112 (alsoreferred to as a support member) that is connected to a rear area of theseat assembly 104.

FIG. 2A is an exploded perspective view of an embodiment of the seatback assembly 102, which is also referred to herein as a height adjustmechanism. As shown in FIG. 2, the support 112 in the illustratedimplementation has a lower end 114 and an opposite upper end 116. Thelower end 114 can have apertures 118 for receiving fasteners 120 tosecure the support 112 in place. In the illustrated implementation,there are optional spacers 122 through which the fasteners 120 arethreaded. The lower end 114 can be angled as shown to suit theparticular configuration, or it may have another suitable shape. As isdescribed in more detail below, a movable portion, or movable heightadjusting assembly, is movable relative to the support 112 which isstationary (unless provided with an optional tilt capability, as isdescribed below).

The support 112 includes at least one generally upright guiding feature,such as one or more guide grooves or slots. In the illustratedimplementation, the support 112 includes a pair of parallel throughslots 124 configured to be positioned generally vertically whenassembled. The support 112 is constructed to have a robust configurationthat does not yield. In some implementations, the support 112 ismachined from solid bar stock steel.

The slots 124 receive guide members, which in the illustratedimplementation are the respective guide members 126 extending from aninner surface 127 of an outer cover 150. Each guide member 126 has alateral width shaped to be slidingly received in one of the slots 124,respectively, and a substantial length so as to ensure that the movableassembly can be extended and retracted smoothly without excess play. Theguide members 126 are secured in the respective slots 124 by a plate 134on an inner side, which is secured by fasteners 136 that extend throughapertures 135 and are received in threaded holes or bores 137 in theguide members 126. In the illustrated implementation, there are twofasteners 136 securing the left side of the clamp plate 134 to a leftguide member 126. There are also two fasteners 136 securing a right sideof the clamp plate 134 to a right guide member 126, but the right sideof the clamp plate 134 has a cut-out or opening 142 shaped to receive anactuator 140 accessible from an exterior surface of the seat backassembly 102 (see, e.g., FIG. 1) that the user can depress or otherwisemanually actuate to allow the user to adjust the position of the seatback 110, i.e., to move it upward or downward. In some implementations,the actuator 140 is a pushbutton actuator.

FIG. 2B is a perspective view of the seat back assembly 102 from a rearside with a portion of the outer cover 150 cut away to show theinteraction of the guide members 126 in the slots 124 and an engagementmember 144. As illustrated, a distal end 145 of the engagement member144 is positioned into one of a series of spaced recesses 147 formed inthe support 112, such as by being spring-biased in a direction towardsthe support 112. The spaced recesses 147 define a height adjustmentrange for the seatback 110. In the illustrated implementation, theengagement member 144 is attached at its lower end to the inner surface127 with fasteners 146 (FIG. 2A).

When the actuator 140 is depressed with sufficient force, a projection149 on the actuator contacts the engagement member 144 and moves thedistal end 145 away from the support 112 and out of engagement with therecess 147. While the distal end is disengaged, the user can adjust theheight of the seat back 110 by grasping the movable assembly (formed bythe outer cover 150, a mating inner cover 152 and the other associatedcomponents coupled thereto) and sliding it upward or downward relativeto the support 112 to a new position. Conveniently, the user can reachbehind with a right hand, depress the actuator 140 with a thumb, and atthe same time use the other four fingers to grasp and move the movablesubassembly. Thus, it is possible to adjust the height of the seat backusing one hand, which is advantageous, particularly in workingenvironments where frequent changes in seating positions are desirable.

As shown in FIGS. 1B and 2B, the actuator 140 can be positioned againstthe inner cover 152 with a mount 150 held in place to permit theactuator to pivot when depressed. As shown in FIG. 2A, optional wearpads 130, 132 can be assembled in contact with the outer and innersurfaces of the support 112. The wear pads, which can made of a nylonplastic or other similar material, can be provided to make components ofthe movable subassembly slide more freely relative to the support 112and to minimize wear from repeated use.

When the actuator 140 is in its at rest position, the engagement betweenthe distal end 145 and the selected one of the recesses 147 providessufficient force to keep the seatback 110 in place and prevent unwantedmovement. Of course, other suitable arrangements to provide suitableengagement and/or clamping forces can be used. The height range andadjustment increment are set to accommodate users of a wide range ofheights and sizes, as well as to accommodate users' different positionson the stool, including a regular seated position and other positions apractitioner might adopt while working that would cause the practitionerto contact some portion of the seat back assembly 102.

As shown in FIG. 2A, a lower cover 154 can be provided, and it can besecured in place, such as to the outer cover 150 as shown, withfasteners 156. The outer cover 150 can be formed of extruded aluminum,or another suitable material. The inner cover 152 and the lower cover154 can be formed of injection molded plastic, such as an injectionmolded polyester and polycarbonate blend, or another suitable material.The inner cover 152 may have a tab 159 or other feature to assist inaligning it with the outer cover 150.

As can be seen in FIGS. 1A, 1B, 2B, 3A-3C, the seat back assembly 102(as well as the related assembly 102′ discussed below) has an exteriorconfiguration that features surfaces that are generally smooth, few ifany sharp corners and substantial generally planar areas. As a result,the actuator 140 can be situated as shown on a forward surface of theassembly adjacent a seat practitioner's back. This positioning has beenfound to allow the practitioner to reach back, such as with his or herright hand, to locate the actuator without needing to view it, and todepress it while grasping the surrounding structure, i.e, the relativelysmooth and uninterrupted surfaces of the inner cover 152 and the outercover 150. In addition, the smooth surfaces of the seat back assemblythat are relatively free of interruptions allow for the stool to becleaned effectively and easily, which is a necessary requirement for thedental operatory environment.

Although described as a height adjustment mechanism for adjusting theheight of the seat back 110, the same components can be configured forother adjusting functions. For example, as shown in FIG. 7 for anassistant's stool 300, the same assembly as the seat back assembly 102can be implemented as a torso bar assembly 102′ to allow a height of atorso bar 302 to be adjusted upward or downward relative to the seat108. This allows an assistant or other occupant to adjust the torso bar302 for a proper height relative to the assistant's size and currentactivity, which may require leaning over the torso bar 302 to access apatient's oral cavity. The assistant's stool 300 is generally similar tothe stool 100, which allows common components to be usedinterchangeably. As illustrated, the stool 300 is fitted with anoptional, rotatable foot rest 304 that is useful to support the user'sfeet when the stool 300 is used at greater heights.

According to another implementation as shown in FIGS. 3A-6D, a stool 200has adjustable armrests, such as a right armrest assembly 160 forsupporting a right armrest 162 and a left armrest assembly 164 forsupporting a left armrest 166 (for convenience, “left” and “right” asused herein refer the seated occupant's left and right). The armrestassemblies 160, 164 are capable of multiple movements to allow thearmrests 162, 166 to be independently positioned in a wide variety ofpositions. Referring to the front side elevation view of FIG. 3A, thearmrests 162, 166 are shown in a regular width position. FIG. 6A is aplan view of the chair 200 with the armrests 162, 166 in the regularwidth position. In FIG. 3B, the armrests 162, 166 have been moved to awide position by adjusting each respective armrest assembly 160, 164relative to an armrest base 158, as is described in detail below. FIG.6B is a plan view of the chair 200 with the armrests 162, 166 in thewide position. In FIG. 3C, the armrests 162, 166 have been rotatedinwardly to a narrow, elbow support position in which the user canconveniently place his or her elbows on the armrests 162, 166. FIG. 6Dis a plan view of the chair 200 with the armrests 162, 166 rotated tothe elbow support position. FIG. 6C is a plan view of the chair 200 withthe armrests 162, 166 rotated to a spread position, which can be used tomove the armrests out of the way for the user's specific activities, aswell as ingress and/or egress.

FIG. 4 is an exploded perspective view of the armrest assembly 160, thearmrest assembly 164 and the armrest base 158, showing the componentsthat allow the relative movements necessary to permit the armrests 160,166 to be positioned in a wide range of positions. FIG. 5 is a sectionedelevation view of the armrest assembly 160 for the right side showingthe components in an assembled state.

Referring to FIGS. 4 and 5, the armrest assembly 160 has an adjustmentknob 172 a with a shaft that extends through a slot 184 a in a supportmember 170 a that supports the armrest 162 and through an alignedopening 186 a in the armrest base 158. The distal end of the shaft isreceived in a pivot hub 190 a. A backer plate 197 a is secured to alower side of the armrest base with fasteners 198 a. There is a frictionadjustment screw 196 a with a threaded end extending outwardly throughthe backer plate 197 a that receives a nut 199 a for adjusting theamount of friction experienced during movements. If necessary, thefriction adjustment screw 196 a can be held in place while the nut 199 ais rotated by inserting an appropriate tool in a slot or recess providedat an end 201 a of the friction screw 196 a.

In the illustrated implementation, there is a series of componentspositioned between the adjustment knob 172 a and the armrest base 158,namely a thrust washer 174 a, a thrust bearing 176 a, a thrust washer178 a, a low friction (e.g., nylon plastic) washer 180 a and another lowfriction (e.g., nylon plastic) washer 182 a. Similarly, there aresimilar components in the assembly below the armrest base 158, includinga friction washer 188 a positioned over the pivot hub 190 a, and afriction isolation bearing stack comprising a thrust washer 192 a, athrust bearing 194 a and a thrust washer 195 a positioned between thepivot hub 190 a and the friction adjustment screw 196 a. A slight gap ismaintained between the support member 170 a and the armrest base 158.

The bearings, hub, washers and friction components provide for smoothpivoting and an adjustable degree of friction to prevent unintendedrotation of the armrests. Desirably, a range of friction is possible,including sufficient friction to keep the armrests in position afteronly incidental contact, but allowing the armrest to be moved freely,without manipulation of other components, when pushed or pulled. Thisprovides users with a positive fee for how components of the stool moverelative to each other.

The adjustment knob 172 a can be tightened to keep the armrest 162 atany desired position. The armrest assembly 164 is a mirror image of thearmrest assembly 160. A yoke 185 and fasteners 187 are used to securethe arm base 158 to part of the chair, such as, e.g., a shaft of thechair.

The stool can include one or more manual controls, e.g., the levers (orpaddles) 201, 203 and/or 205, to allow the user to adjust the positionsof portions of the stool. For example, the leg assembly 106 thatsupports the seat 108 may include a gas cylinder controllable with thelever 201 to assist the user in raising or lowering the seat 108 to adesired height. As another example, the lever 203 may be configured toactuate a tilt adjust mechanism to permit the seat 108 and back 110 tobe angled in unison under tension (such as when a seated user leansagainst it them), to change the tension and/or to lock the seat 108 andback 110 in place and prevent any tilting. The lever 205 may beconfigured to permit the back 110 to be reclined relative to the seat108.

Commonly assigned and concurrently filed applications entitled “SEATASSEMBLY FOR TASK-ORIENTED SEATING” (U.S. Patent Application No. NOT YETASSIGNED) and “ARMREST ASSEMBLY AND STOOL FOR DENTAL PRACTITIONER” (U.S.Patent Application No. NOT YET ASSIGNED) are incorporated herein byreference.

In view of the many possible embodiments to which the disclosedprinciples may be applied, it should be recognized that the illustratedembodiments are only preferred examples and should not be taken aslimiting the scope of protection. Rather, the scope of protection isdefined by the following claims. We therefore claim all that comeswithin the scope of these claims.

We claim:
 1. A height adjusting mechanism for a dentistry stool,comprising: a support member coupleable to the stool adjacent an aftside of a seat of the stool, the support member having at least oneguide groove; a movable height adjusting assembly that is selectivelymovable up and down relative to the support member, the movable heightassembly having a front cover and a rear cover that substantiallyenclose corresponding front and rear engaged portions of the supportmember, wherein at least one of the front cover and the rear covercomprises an inner surface with protruding guide members configured toengage the guide groove in the support member; and a pushbutton actuatorpositionable in a cutout on a front side of the movable height adjustingassembly adjacent a seated user, the pushbutton actuator being manuallyactuatable by the seated user to release the movable height adjustingassembly from a locked position at a current height to allow the seateduser to move the movable height adjusting assembly to a new height. 2.The height adjusting mechanism of claim 1, further comprising a seatback, wherein the seat back is coupled to a distal end of the movableheight adjusting assembly.
 3. The height adjusting mechanism of claim 2,wherein, when assembled, the seat back is spaced along a horizontalfore-aft axis farther from the aft side of the seat than the movableheight adjusting assembly and support member.
 4. The height adjustingmechanism of claim 1, further comprising a torso bar, wherein the torsobar is coupled to a distal end of the movable height adjusting assembly.5. The height adjusting mechanism of claim 1, wherein the support memberhas an angled proximal end with apertures, and wherein the angledproximal end is configured for coupling the support member rearward of aseat of the stool.
 6. The height adjusting mechanism of claim 1, whereinthe pushbutton actuator is positionable within arm's reach of the seateduser and is actuatable using a single hand.
 7. A height adjustingmechanism for a dentistry stool, comprising: a support member coupleableto the stool adjacent an aft side of a seat of the stool; a movableheight adjusting assembly that is selectively movable up and downrelative to the support member, the movable height assembly having afront cover and a rear cover that substantially enclose correspondingfront and rear engaged portions of the support member, wherein the rearcover has a U-shaped cross section, and wherein the front cover isconfigured to fit within the U-shaped cross section; and a pushbuttonactuator positionable in a cutout on a front side of the movable heightadjusting assembly adjacent a seated user, the pushbutton actuator beingmanually actuatable by the seated user to release the movable heightadjusting assembly from a locked position at a current height to allowthe seated user to move the movable height adjusting assembly to a newheight.
 8. A height adjusting mechanism for a dentistry stool,comprising: a support member coupleable to the stool adjacent an aftside of a seat of the stool; a movable height adjusting assembly that isselectively movable up and down relative to the support member, themovable height assembly having a front cover and a rear cover thatsubstantially enclose corresponding front and rear engaged portions ofthe support member, further comprising a lower cover with an openingshaped to receive the support member, the lower cover being configuredfor positioning at a junction of the rear cover and the front coveradjacent their proximal ends; a pushbutton actuator positionable in acutout on a front side of the movable height adjusting assembly adjacenta seated user, the pushbutton actuator being manually actuatable by theseated user to release the movable height adjusting assembly from alocked position at a current height to allow the seated user to move themovable height adjusting assembly to a new height.
 9. The heightadjusting mechanism of claim 1, wherein the pushbutton actuatorcomprises a biased engagement member coupled to an inner surface of themovable height adjusting assembly.
 10. The height adjusting mechanism ofclaim 9, wherein the front cover and the rear cover having smooth outersurfaces to facilitate cleaning.
 11. The height adjusting mechanism ofclaim 9, wherein the biased engagement member is coupled to the rearportion.
 12. The height adjusting mechanism of claim 9, wherein thesupport member comprises a series of spaced recesses, and wherein theengagement member is biased to contact one of the recesses.
 13. Theheight adjusting mechanism of claim 9, further comprising a plateconfigured to be coupled to the rear portion with the support memberpositioned between the plate and the rear portion.